The subject matter presented herein relates to mechanical devices and, more specifically, to devices based on micro-electromechanical (MEMs) and nano-electromechanical (NEMs) technology.
Mechanical devices for numerous applications including provision of circuit breakers and high voltage, high current switching have been large in size and often require large forces to activate the switching mechanism. Such conventional switches also operate at relatively slow speeds. They are often complex and expensive to fabricate. In addition, when contacts of the switching mechanism are physically separated, arcing is known to occur and special circuitry is sometimes deployed to prevent arc current to continue to flow through the switch. Energy associated with the arc may degrade the switch contacts or present a hazardous situation.
Solid-state switches have been employed in high speed applications to switch between conducting state and non-conducting states through controlled application of a voltage. Since solid-state switches do not provide a physical gap between contacts when they are in a non-conducting state, leakage current is normally present. Solid-state switches also impart a voltage drop when in a conducting state due to internal resistances of the devices. Voltage drops and leakage currents result in power dissipation and heat generation under normal operating conditions. These have adverse effects on switch performance and the life of the switch. The inherent leakage current associated with solid-state switches renders them less desirable for use in circuit breaker applications.
Micro-electromechanical system (MEMS) based switching devices are regarded as potential alternatives to macro-electromechanical switches and solid-state switches for certain applications. This is because MEMS-based switches tend to have a low resistance when set to conduct current, and can exhibit no leakage when set to a non-conducting state. Further, MEMS-based switches are expected to exhibit faster response times than conventional electromechanical switches.